PCI enumeration/de-enumeration needs to run single threaded to prevent race conditions with other threads changing the topology. Altering the number of virtual functions was not taking the rescan/remove lock hile adding or removing those virtual functions, so this patch adds that.

Reported-by: Krzysztof Wierzbicki krzysztof.wierzbicki@intel.com Cc: stable@vger.kernel.org Signed-off-by: Keith Busch keith.busch@intel.com --- drivers/pci/pci-sysfs.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 9ecfe13157c0..611abe220b6f 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -591,6 +591,7 @@ static ssize_t sriov_numvfs_store(struct device *dev, if (num_vfs > pci_sriov_get_totalvfs(pdev)) return -ERANGE;

+ pci_lock_rescan_remove(); device_lock(&pdev->dev);

if (num_vfs == pdev->sriov->num_VFs) @@ -627,6 +628,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,

exit: device_unlock(&pdev->dev); + pci_unlock_rescan_remove();

if (ret < 0) return ret;